Beverage products come in a variety of packaging styles. For example, carbonated beverages are supplied in traditional glass bottles, in plastic bottles and in aluminium cans. Wine, by contrast has been traditionally sold in glass bottles, although the use of a cardboard cask container enclosing a bladder is also known and there have been more recent attempts, as yet not commercially widespread, to promote wine in alternative packages such as aluminium cans or even cartons of the type typically used for milk and fruit juice products.
There are underlying reasons driving demand for alternative packaging methods to those traditionally used including the cost of manufacture, the volume able to be stored for domestic applications, the issue of oxidation and/or microbial contamination. We deal with each in turn.
First, it has been recognized that the traditional packaging methods are energy and resource intensive. The extraction and refining of aluminium and subsequent production of aluminium cans is extremely energy intensive. Manufactured aluminium products are therefore regarded as having a very high embodied energy. The environmental consequences of using aluminium in the manufacture of a single use throwaway item are now being subject to significant scrutiny and there is a general desire to move away from such products towards those products that are more sustainable.
Similarly, wine has traditionally been sold in glass bottles. As with aluminium, glass production is also an energy intensive process and the demand exists for more environmentally responsible methods of packaging.
Secondly, long term storage of liquids or beverages is readily achievable in packaging. The success of such packaging has been attributed to the fact that it is cheap to produce and maintains the packaged liquid sterile and free from oxygen ingress and microbial spoilage. However, once opened for consumption, this packaging type offers no protection against oxidation or microbial contamination and the liquid deteriorates rapidly. This is why such packaging is only suitable only for smaller volumes that will be consumed immediately or shortly thereafter upon opening the package.
A further driver for the development of alternative packaging methods is the demand for a packaging method that will allow the user to consume only a portion of the contents of the package without compromising the quality, or reducing the longevity of the remaining package contents.
In the case of carbonated drinks the consumer is inevitably presented with a dilemma on the opening of a can or bottle. Carbonated drinks, as their name implies, rely for their effervescence and taste on the dissolution of carbon dioxide in the liquid drink product. In solution, carbon dioxide forms carbonic acid which also contributes to the taste and feel of the product. In the case of soft drinks the carbon dioxide is added to a base syrup solution and maintained, in the can or bottle, under a head space of carbon dioxide at above atmospheric pressure. The carbon dioxide in solution in the drink is in equilibrium with the carbon dioxide in the head space.
However, once the can or bottle has been opened, the atmosphere above the liquid contents of the package changes. The overpressure carbon dioxide gas escapes (giving the familiar rush of air from the can or bottle) and air in the can or bottle is replaced with air having the typical atmospheric constitution and, at equilibrium, the gas content of the liquid, and more particularly, the carbon dioxide content of the liquid is substantially reduced. This results in the familiar flat drink, generally considered to be unpalatable.
In the case of wine the issues are slightly different. Wine is produced from the fermentation of plant sugars into alcohol by yeasts. Typically the alcohol content of a wine is in the region of 9-15% alcohol by volume. In addition to the alcohol content wines typically contains a myriad of complex organic compounds that contribute to the taste and flavour of the product. Most but not all of these organic compounds, including the alcohol, may be subject to chemical reaction on exposure to atmospheric oxygen producing a chemically altered product. The chemistry of wine is complex and there is merit, in some cases, of exposing a wine to atmospheric oxygen—generally known as allowing a wine to ‘breathe’. However, extended exposure to oxygen can result in the wine being ‘oxidised’, and, as a result, becoming unpalatable. Although various reactions may be involved, oxidation does at least affect the alcohol present in the wine in that prolonged exposure to oxygen will result in alcohol being oxidised to aldehydes and ultimately to acetic acid. Thus, wine from a standard 750 ml narrow necked bottle will deteriorate slowly, but appreciably, after opening such that, in most cases, a noticeable drop in quality of a red wine may be perceived after only a few days at the very most.
As an alternative to the use of a wine bottle, the wine cask has been developed and used successfully, also known as the bag in box (BIB). A wine cask consists of a flexible metallised polymer bladder holding wine attached to a dispensing tap. In use, a wine cask has a limited life span of around 9 months, as the polymer bag is to some degree permeable to oxygen. The BIB is the most common and popular bulk liquid storage packaging that offers intermittent liquid dispensing. The principle of operation of the BIB involves the liquid being contained within a collapsible bag that requires gravity to push the contents out of a dispensing tap.
There are several limitations to the BIB. These are:                (a) Liquids sensitive to oxidation have a limited shelf life in the BIB due to oxygen ingress through the collapsible bag during storage. Forty percent of the oxygen ingress in the BIB occurs as a result of direct oxygen permeability into the stored liquid through the bag itself.        (b) Oxidation further increases by another 60% when the consumer begins dispensing liquid as a result of oxygen ingress through the dispensing tap.        (c) Microbial contamination can enter through the dispensing tap during use.        
The problem of storage and dispensing of a beverage from a larger vessel, without compromising product quality also occurs in connection with beer. Carbon dioxide is, of course entrained in beer during the fermentation process; however, in addition to this many beers are now stored and dispensed from a pressurized keg in which an overpressure of carbon dioxide is used to exclude air from entering the keg. Kegs used for commercial breweries are typically made of aluminium or stainless steel hold around 50 L and require properly maintained equipment to tap and dispense the product. Commercial kegs are essentially unsuitable for domestic use.
However, the demand for domestic at home beer consumption has driven the development of the single use keg, typically of 5 L volume. Each keg comes with an internal C02 compressor, which pushes the beer up the line and prevents the contents of the keg from coming into direct contact with the air. Beer stays fresh for at least 30 days after the keg is tapped. This technology relies on a gas blanket to compress the fluid and results in gas diffusion of carbon dioxide into the fluid. The beverage then acquires excessive gas and can suffer loss of aroma. Accordingly, this technology is unsuitable for non carbonated beverages. The relatively short life of a product stored in a single use keg, after the keg has been breached is also a limitation on the more wide spread use of such a product.
Thus the above solution is an advance from the BIB in that oxidation is reduced effectively due to the liquid being stored within an impermeable container (tin can). However, this packaging design creates other limitations and as mentioned, does not eliminate microbial invasion through the dispensing valve. The principle of operation of such kegs involves a supply of constant gas pressure (from a gas cylinder and regulator) provided within the packaging to push out the liquid contents through the dispensing valve. The design limitations of this packaging are:                (a) The gas used to push out the liquid is in direct contact with the liquid, effectively equilibrating with the liquid and changing its gaseous composition continuously, affecting the taste so that it becomes undrinkable within 30 days of consumer activation.        (b) A further contributing factor that causes the liquid quality to reduce is the formation of headspace within the packaging as a result of liquid volume reducing during consumer dispensing. This headspace further cause's aroma to be lost from the liquid due to the law of equilibrium.        (c) The packaging concept is not suitable for still liquids as gas acquisition affects the liquid specifications and taste.        (d) The dispensing tap allows microbial ingress that can cause spoilage of the liquid.        (e) The packaging concept is not suitable for all carbonated liquids.        
Thus whilst specialised packaging aimed at reducing oxidation post opening and during consumer dispensing have allowed for larger liquid volumes to be packaged and sold, other factors that contribute to stored liquid deterioration, such as microbial contamination, have not been addressed in any of these packaging solutions.
An attempt to overcome microbial contamination and the ingress of oxygen through the tap of the BIB has resulted in the development of aseptic taps. Whilst such a tap can reduce oxygen ingress into the BIB by 60% the additional 40% due to oxygen permeability through the surface of the collapsible bag itself is not addressed by such a tap.
There is no known solution for current kegs that suffers from contamination, loss of volatile aroma from the liquid due to headspace formation and over gassing due to direct contact between the liquid and the pressurised gas.
The present invention is addressed to the above problem and seeks to provide an alternative to current storage solutions for dispensing of beverages or even just for storage of beverages.